The present invention relates to an arrangement for enhancing the cooling capacity of portable personal computers. More particularly, the invention is directed to the aspect of enhancing the power dissipation of portable personal computers (PCS) by conducting heat through a heat pipe arranged in a hinge structure interconnecting a display panel with a bottom keyboard housing, and conducting the heat into an area at the rear of the display panel.
The capacity and performance of portable personal computers, such as laptop computers, notebook computers or the like, has recently been enhanced to such an extent that; for example, since the beginning of 1996, the thermal dissipation requirements of portable personal computers (PCs) have increased from about 10 watts to 20 watts and even higher values. This increase in the thermal dissipation requirements is a result of ever increasing CPU performance and additional functionality; such as DVD, modem, audio and the like, which are provided by future PCs. As eludicated in an article by Albert Yu, "The Future of Microprocessors", IEEE Micro, December 1996, pages 46 through 53, the trend of increasing power dissipation in the form of heat for portable personal computers will continue in the foreseeable future. Thus, at the widely employed A4 form factor for a portable personal computer; for instance, the cooling limit for a portable PC without a cooling fan is currently approximately 15 to 20 watts. Thus, providing a greater cooling capacity than the current limits in order to meet the anticipated thermal dissipation requirements of future portable personal computers, represents not only a potential competitive advantage in industry, but also provides a significant product differentiation from currently available and commercially sold portable personal computers.
In order to meet the requirements for enhancing the cooling capacities of portable personal computers, pursuant to the invention, a personal computer, especially such as a laptop computer having an openable display panel and a keyboard articulated to the bottom thereof, incorporates a heat pipe for conducting heat through the hinge of the display panel which connects the latter to the keyboard, and which essentially dumps the heat in an area towards the rear of the display. At that location, the availability of an increased surface area and the presence therein of relatively few electronics facilitates an increased degree of heat dissipation into the ambient air or surroundings.
In addition to the foregoing function, the arrangement of employing the heat pipe as a component of the hinge structure of the laptop computer enables current carrying conductors to extend therethrough to form a flexible Faraday cage around the conductors for electromagnetic interference (EMI) protection of the conductors which are attached to the body or housing of the computer at one end and to the display at the other end.
An extremely valuable area for dissipating heat on a laptop computer is the back of the display. This area is normally not used effectively because very few heat generating components are located in this area. Furthermore, it is difficult to conduct more heat to this area from the lower portion or keyboard of the laptop computer because the means to implement this has to pass through a hinge forming the interconnection between the lower portion of the laptop computer and the display panel. Additionally, it is difficult to locate heat generating components, such as the CPU, in this area because the large number of signal wires which must pass through the hinge in order to communicate with the other components located in the lower portion of the laptop computer.
A well known device for conducting heat efficiently is a heat pipe. The heat pipe normally consists of a length of tubing, usually comprising copper, which is hermetically sealed with a fluid contained therein under a critical pressure such that, when one end of the pipe is in contact with a warm body, the heat from the warm body causes the fluid to boil. The normally vaporous fluid travels to the colder end of the tube and condenses thus taking energy therewith to the other end of the tube. Conductivities of greater than 100 times that of copper can be achieved in this manner. Moreover, the length of the tube has little impact on the conductivity of the heat pipe.